Oxygen generator having honeycomb structure

Abstract

An oxygen generator having a honeycomb body made of oxygen ion conducting material separates oxygen from a first gas, such as air. The honeycomb body has a plurality of generally parallel first and second channels coated with a layer of porous metal conductor which serve as electrodes. The first and second channels are arranged in alternating rows across the face of the honeycomb and the respective electrodes therein are oppositely charged by connection to a voltage source. Oxygen ions from a first gas in the first channels are caused to tranit across the channel walls to the second channels under an applied voltage. Oxygen generated in the second channels may be collected in a manifold through a set of third channels which intersect the sealed second channels, and used in applications such as home breathing apparatus'. Additional features are included in the honeycomb body and in the design of manifolds to facilitate the supply of a first gas and collection of oxygen. Preferably operating at elevated temperatures, the oxygen generator may also incorporate a heater and valve for start up and a heat exchanger for thermally efficient steady state operation.

What is claimed is: 
     
       1. An oxygen generator for separating oxygen from a first gas and generating therefrom a second gas having a high concentration of oxygen, comprising: (1) a body comprising one or more cells, each of said cells having:   (a) an extruded, one-piece honeycomb body comprised of oxygen ion conductive material and including:   (b) a plurality of faces including at least a first, second, and third face; and   (c) a plurality of first and second channels defined by channel walls, and at least one third channel disposed therein, wherein:   (i) said first channels extend from inlet openings in said first face of said honeycomb body to outlet openings in said second face of said honeycomb body, to receive a first gas having a partial pressure of oxygen therein; and   (ii) said second channels extend generally parallel to said first channels from openings in said first face to openings in said second face;   (iii) said at least one third channel extending laterally to an oxygen outlet opening in said third face, and each of said at least one third channels intersecting at least one of said second channels at a point between said first and second faces of said honeycomb body, such that each of said second channels is intersected by at least one third channel to provide flow communication therebetween, allowing oxygen generated in said second channels to flow outward therefrom through said third channels; and   (d) electrodes disposed on said channel walls in said first and second channels;   (e) means for electrically interconnecting said electrodes in said first channels;   (f) means for electrically interconnecting said electrodes in said second channels;   (g) means for sealing said second channels at said first and second faces;   (2) a voltage source and means disposed on said body for electrically connecting said electrodes in said one or more cells to said voltage source;   (3) means for collecting oxygen enclosing said oxygen outlet opening.   
     
     
       2. An oxygen generator as recited in claim 1 wherein said oxygen ion conductive material is selected from the group consisting of: Bi 2  O 3  :Nb 2  O 5  or Bi 2  O 3  :Y 2  O 3  -based ceramic material. 
     
     
       3. An oxygen generator as recited in claim 1 wherein said body comprises two or more of said cells electrically connected in parallel. 
     
     
       4. An oxygen generator as recited in claim 1 wherein said means for electrically interconnecting said electrodes disposed in said first channels comprises: a metallic conductive layer disposed on at least one face of said honeycomb body connecting to said electrodes disposed in said first channels of said one or more cells.   
     
     
       5. An oxygen generator as recited in claim 1 wherein: said first channels and said second channels are arranged in alternating rows; and   said means for electrically interconnecting said electrodes disposed in said second channels of a cell comprises one or more electrical conductors, ones of said electrical conductors being electrically interconnected to the electrodes in at least one row of said second channels, and said one or more electrical conductors further electrically connected to others of said one or more electrical conductors disposed in the same cell.   
     
     
       6. An oxygen generator as recited in claim 1 wherein said means for electrically interconnecting said electrodes disposed in said second channels comprises: one or more third electrodes disposed in one or more of said third channels electrically connecting with said electrodes disposed in said second channels, and   one or more electrical conductors interconnecting said third electrodes.   
     
     
       7. An oxygen generator as recited in claim 6 wherein said electrodes disposed in said third channels comprise a layer of metallic conductor disposed on the surfaces of one or more of said third channels. 
     
     
       8. An oxygen generator as recited in claim 6 further comprising means for protecting and insulating at least one of said one or more electrical conductors interconnecting said third electrodes. 
     
     
       9. An oxygen generator as recited in claim 1 further comprising: means for supplying said first gas to said first channels at one of said first and second faces; and   means for receiving spent first gas from said first channels at the other of said first and second faces.   
     
     
       10. An oxygen generator as recited in claim 9 wherein said means for supplying a first gas to said first channels is electrically isolated from said body. 
     
     
       11. An oxygen generator as recited in claim 9 wherein said means for receiving is electrically isolated from said body. 
     
     
       12. An oxygen generator as recited in claim 9 wherein: said means for supplying comprises an intake manifold, said means for receiving comprises an exhaust manifold, and said means for collecting oxygen comprises an oxygen manifold; and   said intake, exhaust and oxygen manifolds are formed by the assembly of two pieces.   
     
     
       13. An oxygen generator as recited in claim 9 further comprising: a heat exchanger,   means for connecting said heat exchanger to each of said means for supplying, means for receiving and means for collecting oxygen for pre-heating said first gas entering said means for supplying with heat from spent first gas and oxygen from said first and second channels.   
     
     
       14. An oxygen generator as recited in claim 1 wherein said first and said second channels are generally square in cross section. 
     
     
       15. An oxygen generator as recited in claim 1 wherein: said first and second channels are arranged in alternating rows; and   said body further comprises at least a first and a second column each column having one or more cells each, wherein:   the first column begins with a row of said first channels and the second column begins with a row of said second channels;   said first and second columns end with different rows of said first or second channels; and   subsequent ones of said columns have different first rows of first or second channels alternating as aforesaid, and different last rows of first or second channels alternating as aforesaid.   
     
     
       16. An oxygen generator as recited in claim 1: wherein said body further comprises:   at least two columns of one or more cells each; and   at least one separating wall disposed between adjacent ones of said at least two columns, said separating wall positioned between said third faces of said one or more cells forming said columns; and   wherein said means for collecting oxygen comprises an oxygen manifold disposed in said separating wall to collect oxygen from said at least one third channel opening to said third faces.   
     
     
       17. An oxygen generator as recited in claim wherein: said body is comprised of two or more cells; and   said means for electrically connecting said electrodes in said two or more cells to a voltage source comprises:   one or more strips of electrical conductor disposed on at least one face of each of said cells connecting adjacent cells in series; and   two or more leads connecting the first and the last of said series of cells to opposite poles of said voltage source.   
     
     
       18. An oxygen generator as recited in claim 17 further comprising means for protecting and insulating at least one of said one or more strips of said electrical conductor. 
     
     
       19. An oxygen generator as recited in claim 18 wherein said protecting and insulating means comprises a protective cap of ceramic. 
     
     
       20. An oxygen generator as recited in claim 18 wherein said means for protecting and insulating comprises one or more depressions in the surface of said body wherein at least one of said one or more strips of electrical conductor are disposed. 
     
     
       21. An oxygen generator as recited in claim 1 further comprising means for controlling said voltage source. 
     
     
       22. An oxygen generator as recited in claim 21 wherein said means for controlling further comprises: one or more thermocouples disposed on said body; and   a voltage regulator electrically connected to said voltage source, and further connected to and responsive to said one or more thermocouples.   
     
     
       23. An oxygen generator as recited in claim 1 further comprising means for supplying a first gas to said first channels, and said means for supplying a first gas to said first channels further including a valve for controlling the supply of said first gas to said first channels. 
     
     
       24. An oxygen generator as recited in claim 23 wherein said means for supplying a first gas to said first channels further comprises a start-up heater for heating said first gas supplied to said first channels and initiating flow in a desired direction thereinto. 
     
     
       25. An oxygen generator as recited in claim 24 further comprising means for automatically operating said valve sequentially with said start-up heater for automatic start-up of said oxygen generator. 
     
     
       26. An oxygen generator as recited in claim 24 further comprising: one or more thermocouples disposed on said body; and   means for controlling said start-up heater connected to said start-up heater, and further connected to and responsive to at least one of said one or more thermocouples.   
     
     
       27. An oxygen generator as recited in claim 1 wherein said means for collecting oxygen is electrically isolated from said body. 
     
     
       28. An oxygen generator as recited in claim 1 further comprising: means for supplying said first gas to said first channels;   an exhaust manifold for receiving said first gas from said first channels;   a flow control valve located upstream of said means for supplying;   a heater disposed in said means for supplying downstream of said flow control valve; and   a heat exchanger for pre-heating said first gas entering said means for supplying with heat from the said spent first gas and said oxygen from said first and second channels.   
     
     
       29. An oxygen generator for separating oxygen from a first gas and generating therefrom a second gas having a high concentration of oxygen, comprising: (1) a body comprising:   (a) one or more cells, each of said cells having:   (i) a honeycomb body comprised of oxygen ion conductive material and including:   a plurality of faces including at least a first, second, and third face; and   a plurality of first and second channels, and at least one third channel disposed therein, wherein:   said first channels extend from inlet openings in said first face of said honeycomb body to outlet openings in said second face of said honeycomb body, allowing a first gas having a partial pressure of oxygen to flow therethrough;   said second channels extend generally parallel to said first channels between said first and second faces and are sealed at said first and second faces;   said first channels and said second channels comprise alternate rows of channels in said honeycomb body; and   said at least one third channel extends laterally to an oxygen outlet opening in said third face, and is positioned to intersect at least one of said second channels at a point between said first and second faces of said honeycomb body, allowing oxygen generated in said at least one second channel to flow outward therefrom through said third channels, each of said at least one third channels intersecting at least one row of said second channels;   (ii) electrodes disposed in said first and second channels;   (iii) means for electrically interconnecting said electrodes in said first channels;   (iv) means for electrically interconnecting said electrodes in said second channels; and   (b) means for electrically connecting said electrodes in said one or more cells together;   (2) a voltage source connected to said means for electrically connecting to apply a voltage between said electrodes in said first and second channels; and   (3) means for collecting oxygen enclosing said oxygen outlet opening.   
     
     
       30. An oxygen generator as recited in claim 29 wherein said oxygen ion conductive material comprises Bi 2  O 3  :Nb 2  O 5  -based ceramic material. 
     
     
       31. An oxygen generator as recited in claim 29 wherein said means for electrically interconnecting said electrodes disposed in said second channels further comprises at least one third electrode disposed in said at least one third channel electrically connecting with said electrodes disposed in said second channels intersected by said at least one third channel. 
     
     
       32. An oxygen generator as recited in claim 29 wherein said body further comprises at least a first and a second column having one or more cells each.   
     
     
       33. An oxygen generator as recited in claim 32 wherein: the first column begins with a row of said first channels and the second column begins with a row of said second channels, and   said first and second columns end with different rows of said first or second channels, and   subsequent ones of said columns have different first rows of first or second channels alternating as aforesaid, and different last rows of first or second channels alternating as aforesaid.   
     
     
       34. An oxygen generator as recited in claim 32 further comprising at least one separating wall disposed between adjacent ones of said at least two columns, said separating wall positioned between said third faces of said one or more cells forming said columns, and wherein said means for collecting oxygen comprises an oxygen manifold disposed in said separating wall to collect oxygen from said at least one third channel opening to said third faces. 
     
     
       35. An oxygen generator as recited in claim 29 further comprising means for automatically controlling said voltage source including: at least one thermocouple disposed on said honeycomb body; and   a voltage regulator connected to said voltage source, and further connected to and responsive to said at least one thermocouple.   
     
     
       36. An oxygen generator as recited in claim 29 further comprising: means for supplying a first gas through said inlet openings to said first channels; and   means for receiving spent first gas from said first channels through said outlet openings.   
     
     
       37. An oxygen generator as recited in claim 36 wherein said means for supplying a first gas to said first channels further comprises a start-up heater for heating said first gas and initiating the flow of gas flow through said first channels in a desired direction. 
     
     
       38. An oxygen generator as recited in claim 37 wherein said means for supplying further comprises: a valve for controlling the supply of said first gas to said first channels; and   means for automatically operating said valve in cooperation with said start-up heater to initiate the flow of gas through said first channels in a desired direction;   whereby said start-up heater may be operated to initiate flow in said first channels towards said outlet openings, and said valve opened automatically thereafter.   
     
     
       39. An oxygen generator as recited in claim 36 further comprising: a heat exchanger; and   means for connecting said heat exchanger to said means for supplying said first gas and at least one of said means for receiving spent first gas and said means for collecting oxygen to pre-heat said first gas supplied to said oxygen generator.   
     
     
       40. An oxygen generator as recited in claim 36 further comprising: a valve for controlling the supply of said first gas to said first channels located upstream of said means for supplying;   a start-up heater disposed in said means for supplying a first gas, said means for receiving spent first gas, and said means for collecting oxygen to pre-heat said first gas entering said means for supplying with heat from said spent first gas and said oxygen collected from said third channels.